Natural selection leads to

• A. A decrease in all traits in a population
• B. Random changes with no relation to survival
• C. Favouring individuals with advantageous traits, increasing their frequency
• D. Immediate genetic changes in every generation

Answer: (C)

Natural selection is the process by which individuals with traits that help them survive and reproduce leave more offspring. Those advantageous traits become more common in the population over generations because the fitter individuals contribute more genes to the next generation. That’s why the best choice describes natural selection as favoring advantageous traits and increasing their frequency.

The other ideas don’t fit because natural selection doesn’t cause a universal decrease in all traits, nor does it produce random changes unrelated to survival. And changes aren’t guaranteed to occur in every generation in an immediate, uniform way—the frequency of traits shifts based on how much those traits improve fitness, which can vary from generation to generation.